This application claims the priority of Korean Patent Application No. 2002-34650, filed on Jun. 20, 2002, in the Korean Intellectual Property Office, which is incorporated herein in its entirety by reference.
1. Field of the Invention
Apparatuses and methods consistent with the present invention relate to an actuator using an organic film membrane and a manufacturing method thereof and, more particularly, to an actuator utilizing an organic membrane used in an inkjet head and a pressure sensor micro pump and a manufacturing method thereof.
2. Description of the Related Art
As shown in FIGS. 1 and 2, a conventional actuator including a membrane 3 driven by an electrostatic force or a piezoelectricity force is fabricated by integrally forming the membrane 3 on which a driving electrode or a piezoelectric material 5 is formed and a frame 2 supporting the membrane 3 on a silicon substrate 1. When manufacturing such an actuator, a micromachining technology is applied to a silicon wafer.
In this case, a wet etching using a pattern mask is performed in the micromachining process of the silicon wafer. The membrane and the frame supporting the membrane using the wafer are formed by wet etching. During the wet etching, a cavity 4 is formed under the membrane 3 as shown in FIGS. 1 and 2. When forming the cavity 4, an isotropic etchant is used, so an opening width D of the cavity 4 on the lower surface of a substrate is excessively large compared with the width d of the membrane. In other words, the cavity 4 having a width D larger than the width d of the membrane 3 is formed on the lower surface of the substrate 1. Accordingly, the width W of the substrate must be increased considering the width of the frame 2 that is designed to have an appropriate strength. Thus, the size of the substrate must be increased.
In addition, in order to drive the membrane 3, a piezoelectric material is deposited on the membrane 3 or the membrane 3 is bonded to another wafer, and the membrane 3 is driven by an electrostatic force or an electromagnetic force.